1. Very nice, fluid, rich way to edit.
2. When using Command + <- (back arrow) on mac, equivalent to Alt Back Arrow, you should ask if you want to leave project, regardless if it was saved. First time users wont understand at first that you need to click many times in a text box to select THEN edit it, therefore they will not go to top of word/sentence but instead they will leave the current project and go back to project creation or dashboardm, therefore creating frustation.
3. I had a very bad UX case: I went back to dashboard, and came back to upload logo, just to find that my text had been erased and replaced by the original LOREM IPSUM text (effectively, I LOST my write-up work). I believe this is a history navigation issue, but the result is that I lost my page. I could get around this and correct the damage because I had published the evolved version earlier and did not refresh my published page, but you need to check this as this is a deal-breaker when you're authoring.
This is a great tool and if you keep the excellent look and feel, reliability both in UX and hosting if you get it is going to be the make or break part of the equation.
Good luck, and count me in if you need debug and assistance.